Articles | Volume 20
Sci. Dril., 20, 21–32, 2015
Sci. Dril., 20, 21–32, 2015

Progress report 17 Dec 2015

Progress report | 17 Dec 2015

The Volta Grande do Xingu: reconstruction of past environments and forecasting of future scenarios of a unique Amazonian fluvial landscape

A. O. Sawakuchi1, G. A. Hartmann2, H. O. Sawakuchi3, F. N. Pupim1, D. J. Bertassoli1, M. Parra4, J. L. Antinao5, L. M. Sousa6, M. H. Sabaj Pérez7, P. E. Oliveira1, R. A Santos1, J. F. Savian8, C. H. Grohmann4, V. B. Medeiros1, M. M. McGlue9, D. C. Bicudo10, and S. B. Faustino10 A. O. Sawakuchi et al.
  • 1Institute of Geosciences, University of São Paulo, Rua do Lago, 562, São Paulo, SP, 05508-080, Brazil
  • 2Coordination of Geophysics, National Observatory, Rua General José Cristino, 77, Rio de Janeiro, RJ, 20921-400, Brazil
  • 3Environmental Analysis and Geoprocessing Laboratory, Center for Nuclear Energy in Agriculture, University of São Paulo, Av. Centenário, 303, Piracicaba, SP, 13400-970, Brazil
  • 4Institute of Energy and Environment, University of São Paulo, Av. Prof. Luciano Gualberto 1289, São Paulo, SP, 05508-010, Brazil
  • 5Desert Research Institute, Division of Earth and Ecosystems Sciences, 2215 Raggio Parkway, Reno, NV 89512, USA
  • 6Federal University of Pará, Campus de Altamira, Rua Coronel José Porfírio, 2514, Altamira, PA, 68372-040, Brazil
  • 7The Academy of Natural Sciences, 1900 Benjamin Franklin Parkway, Philadelphia, PA 19103, USA
  • 8Institute of Geosciences, Federal University of Rio Grande do Sul. Avenida Bento Gonçalves, 9500, Porto Alegre, RS, 91501-970, Brazil
  • 9Department of Earth and Environmental Sciences, University of Kentucky, Lexington, KY 40506, USA
  • 10Department of Ecology, Instituto de Botânica, SMA. Av. Miguel Stéfano, 3687, São Paulo, SP, 04301-012, Brazil

Abstract. The Xingu River is a large clearwater river in eastern Amazonia and its downstream sector, known as the Volta Grande do Xingu ("Xingu Great Bend"), is a unique fluvial landscape that plays an important role in the biodiversity, biogeochemistry and prehistoric and historic peopling of Amazonia. The sedimentary dynamics of the Xingu River in the Volta Grande and its downstream sector will be shifted in the next few years due to the construction of dams associated with the Belo Monte hydropower project. Impacts on river biodiversity and carbon cycling are anticipated, especially due to likely changes in sedimentation and riverbed characteristics. This research project aims to define the geological and climate factors responsible for the development of the Volta Grande landscape and to track its environmental changes during the Holocene, using the modern system as a reference. In this context, sediment cores, riverbed rock and sediment samples and greenhouse gas (GHG) samples were collected in the Volta Grande do Xingu and adjacent upstream and downstream sectors. The reconstruction of past conditions in the Volta Grande is necessary for forecasting future scenarios and defining biodiversity conservation strategies under the operation of Belo Monte dams. This paper describes the scientific questions of the project and the sampling surveys performed by an international team of Earth scientists and biologists during the dry seasons of 2013 and 2014. Preliminary results are presented and a future workshop is planned to integrate results, present data to the scientific community and discuss possibilities for deeper drilling in the Xingu ria to extend the sedimentary record of the Volta Grande do Xingu.